Invention Grant
- Patent Title: Longest prefix match lookup using hash function
- Patent Title (中): 使用哈希函数的最长前缀匹配查找
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Application No.: US11353841Application Date: 2006-02-14
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Publication No.: US07702630B2Publication Date: 2010-04-20
- Inventor: Claude Basso , Jean L. Calvignac , Gordon T. Davis , Piyush C. Patel
- Applicant: Claude Basso , Jean L. Calvignac , Gordon T. Davis , Piyush C. Patel
- Applicant Address: US NY Armonk
- Assignee: International Business Machines Corporation
- Current Assignee: International Business Machines Corporation
- Current Assignee Address: US NY Armonk
- Agency: Driggs, Hogg, Daugherty & Del Zoppo Co., LPA
- Agent James A. Lucas
- Main IPC: G06F7/00
- IPC: G06F7/00

Abstract:
A method and apparatus are used for finding the longest prefix match in a variable length prefix search when searching a direct table within a routing table structure of a network processor. The search through the routing table structure is expedited by hashing a first segment of an internet protocol address with a virtual private network number followed by concatenating the unhashed bits of the IP address to the result of the hash operation to form an input key. Patterns are compared a bit at a time until an exact match or the best match is found. The search is conducted in a search tree that provides that the matching results will be the best possible match.
Public/Granted literature
- US20060173831A1 Longest prefix match lookup using hash function Public/Granted day:2006-08-03
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